Typical loading docks provide an area for trucks to back up next to an elevated platform of a building so that cargo can be readily transferred between the truck and the building. Some loading docks include equipment, such as dock levelers and/or vehicle restraints. Dock levelers provide an adjustable bridge between the platform and the truck bed. Vehicle restraints help prevent the truck from prematurely driving away from the platform.
To reduce the likelihood of a truck accidentally striking or crushing personnel that might be in the area, some loading docks might have various vehicle and/or personnel sensing systems. Although such systems might determine whether a person is within a certain area while a vehicle is present, such systems do not address certain conditions where an early warning signal or a preliminary alert might be helpful even though a collision is neither imminent nor likely to occur.